In general, tablets having capsule-type, elliptical or circular cross-sections have been produced in large quantities through automated processes, resulting in defective products during a process in which the tablets are discharged, rather than failure due to a component or dose.
Accordingly, there has been demand for a process of inspecting external defects, such as the adhesion or contamination of foreign matter, cracks or partial damage due to contact or impact between tablets, deformation or printing defects, or the like.
The process of inspecting the appearance of tablets is changing from a visual inspection performed by operators to an automatic inspection using automatic inspection apparatuses. Various types of automatic inspection devices for such automatic inspection have been proposed.
When automatically inspecting tablets using an automatic inspecting apparatus, a method, in which images of one sides of the tablets may be obtained by imaging the tablets using an imaging device during transfer of the tablets, and in which the other sides of the tablets are imaged using the imaging device during reversing positions of the tablets while being transferred, images of one side surfaces and the other side surfaces of the tablets subsequently being processed, thereby inspecting the existence or nonexistence of defects, has generally been adopted.
An example of such a technique is disclosed in Japanese Patent Laid-Open Publication No. 11-51873, relating to an apparatus for inspecting an appearance of a tablet, in which suction grooves or receiving grooves for holding tablets are formed in a circumferential surface of a transfer drum with predetermined intervals therebetween. Such an appearance inspection apparatus needs to have tablets supplied at a constant speed and interval by a supply unit in order to supply the tablets to the suction grooves formed at regular intervals around the transfer drum.
Thus, it may be difficult and complicated to precisely match a rotation speed of the transfer drum and the feed speed and interval in the supply unit. In detail, it may also be difficult to change the inspection speed depending on the shape of tablets or the difficulty of the inspection.